• Economic and Environmental Geology
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• v.43 no.1
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• pp.53-66
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• 2010

We report petrologic characteristics including $^{40}Ar-^{39}Ar$ absolute ages of the subsurface lavas recovered from borehole cores in two islets, Marado and Gapado, off the southwestern coast of Jeju in southernmost Korea and discuss on the volcanism in the region. The lavas in Gapado are apparently divided into one unit with bright colored, aphanitic texture and sheet jointed, and another unit with dark colored and massive. The outcrops often show differentially weathered pattern due to textural difference. While, the lavas in Marado have vesicular and glomerporphyric texture, even though each lava flow unit in Marado has slight unique texture with variation of vesicularity and phenocrysts. The chemical composition of rock core samples from Gapa borehole and Mara borehole shows that the lavas from Gapado and Marado are classified into basaltic trachyandesite($SiO_2$ 52.6-53.6 wt%, $Na_2O+K_2O$ 7.3-7.5 wt%) and tholeiitic andesite($SiO_2$ 51.7-52.8 wt%, $Na_2O+K_2O$ 3.6-4.1 wt%), respectively. The measured $^{40}Ar-^{39}Ar$ plateau ages range from $824{\pm}32\;Ka$(MSL -69 m) to $758{\pm}\;Ka$(MSL 19 m) for core samples of Gapa borehole and $259{\pm}168\;Ka$(MSL -26 m) for a core sample of Mara borehole, respectively. The absolute age of Gapado basaltic trachyandesite is well correlated with that of Sanbangsan trachyte(Won et al., 1986). Meanwhile, the age of a sample in Marado has $259{\pm}168\;Ka$(MSL -26 m) with poor plateau age formation and high error range. We report the data in caution but the rock composition and absolute age of Marado tholeiitic andesite are relatively correlated with those of lava units from Duksu and Sangmo-2 boreholes, indicating the volcanism during 260-150 Ka. On the basis of interpretation of occurrences of exposed and subsurface volcanic rocks of the study area, stratigraphic relationship with adjacent borehole cores and the bathymetry chart of surrounding area, it indicates that the lavas in Gapado were formed around 800 Ka during relatively early stage of volcanic activity in Jeju Island. Meanwhile, Marado may have originated around 260-150 Ka during relatively young stage of volcanism in Jeju Island. It is inferred that the volcanisms have originated in land and these islets were individual ancient volcanoes. The apparent topography has been re-shaped by tidal erosion due to transgression.

• Economic and Environmental Geology
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• v.26 no.2
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• pp.129-134
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• 1993

At the Janggun mine, boulangerite usually occurs as needles or irregularly-shaped grains, up to $500{{\mu}m}$ in longer dimensions, closely associated with galena, minerals of a tetrahedrite-freibergite series and bournonite in the peripheries of South A and B orebodies and the zone of manganoan carbonates surrounding them. In some places, especially at the top of South B orebody, it occures as "feather ore" consisting of its fine needles or "hairs" in small drusy cavities together with fine-grained euhedral galena, pyrite, manganoan carbonates, quartz, etc. In reflected light, it is bluish grey in colour exhibiting moderate bireflectance and is strongly anisotropic without any internal reflections. Reflectance in air is $R_{max}=43.2$, $R_{min}=35.7$ percent at wavelength of 580 nm, and VHN: $146-173\;kg/mm^2$ at a 50 g-load. The chemical composition on the average from 23 complete spot analyses by electron microprobe is, Pb 56.1, Sb 25.1, S 18.5, Total 99.6 (all in weight percent); the corresponding chemical formula calculated on the basis of S=11 is; $Pb_{5.16}Sb_{3.93}S_{11.0}$ which fulfils approximately the ideal formula $Pb_5Sb_4S_{11}$. The strongest reflections on the X-ray diffraction pattern are; $3.73\;{\AA}\;(10)$, $3.22\;{\AA}\;(5)$, $3.03\;{\AA}\;(4)$ and $2.82\;{\AA}\;(5)$ and the pattern is in harmonic with space group $C^5_{2h}-P2_1/a$. From the textural evidence of the microscopic observations, the mineral is considered to have been formed at the latest stage of hydrothermal lead-zinc-silver mineralization.

• Korean Journal of Environmental Biology
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• v.26 no.2
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• pp.66-75
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• 2008

The level of genetic diversity and genetic relationships among Korean ring-necked pheasant (Phasianus colchicus karpowi) habitat and subspecies have been investigated based on Inter Simple Sequence Repeat (ISSR) markers. Wild and domesticated Korean ring-necked pheasant, hybrids between domesticated Korean ring-necked and foreign subspecies, and four foreign subspecies; Chinese ring-necked (P. c. torquatus), Melanistic mutant (P. c. mut. tenebrosus), XL White (P. c. mut) and Southern green (P. c. versicolor) were used for comparison. On the basis of the results of AMOV A, 94.08% of genetic diversity in Korean ring-necked was allocated among individuals within habitat differences. Estimate of $\Phi$st, which represents the degree of genetic differentiation among habitats was 5.9%. Based on the dendrogram reconstructed by UPGMA, Yangpyung habitat of the eight habitats turned out to be distinct from others habitat. Interestingly, domesticated Korean ring-necked and hybrid mixture showed closer genetic relationship with four foreign subspecies than Korean ring-necked. As a consequence of AMOVA, 96.63% of genetic diversity in four foreign subspecies was allocated among individuals within subspecies. Estimate of $\Phi$st representing the degree of genetic differentiation among subspecies was 3.4%, which was lower than that among habitats of Korean ring-necked. The lower level of genetic difference among four foreign subspecies showed that these subspecies were genetically closer even though they were morphologically classified into four different subspecies. When seven habitats of Korean ring-necked pheasant and four foreign subspecies were divided into Korean and Foreign Pheasant Groups, respectively, more than 17% of genetic diversity was allocated between groups (about 4% among habitats/subspecies within groups). This observation implied that Korean ring-necked pheasant is genetically quite different from four foreign subspecies. On the basis of cluster analysis, three foreign subspecies (Chinese ring-necked pheasant, Melanistic mutant pheasant, and XL White pheasant) formed a distinct group with domesticated Korean ring-necked pheasant and hybrid mixture at 98% confidence interval.

• Food Science of Animal Resources
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• v.23 no.2
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• pp.161-167
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• 2003

Identification of salmonellosis-infected commercial poultry flocks has become a pivotal component of efforts to reduce incidence of egg-associated transmission of S. enteritidis and S. typhimurium to humans. As a basic study for sanitary control of S. enteritidis and S. typhimurium, main food-borne pathogenic bacteria in eggs produced by domestic hens, commercial egg samples were tested for specific antibodies to whole cells of S. enteritidis and S. typhimurium and outer membrane protein(OMP) of S. typhimurium by ELISA to detect infection of S. enteritidis and S. typhimurium in various groups of hens. When the antibody titers of yolks from three commercial brand eggs were tested after diluting in the ratio from 1:100 to 1:1,600 with double dilution method, ELISA values of the specific antibodies could be shown as differences in dilution patterns by comparing with negative control egg. When the antibody titers of the yolks from two commercial brand eggs were tested after diluting in the ratio of 1:200 and 1:1,000, ELISA values of specific antibodies were different among same brand eggs. When the antibody titers of yolks from five eggs sampled randomly from twenty one commercial brand eggs were tested after diluting in the ratio of 1:1,000, ELISA value of the specific antibodies were shown generally high. ELISA values of 28.5, 30, and 28.5% of yolks from 21 brand eggs were shown low and similar to negative control egg in antibody titers to whole cells of S. enteritidis and S. typhimurium and OMP of S. typhimurium, respectively. The results demonstrated that ELISA test of egg yolk antibody could provide a highly sensitive indicator to detect contamination of S. typhimurium and S. enteritidis in poultry, and could be used effectively to reduce incidence of S. typhimurium and S. enteritidis infection in poultry.

• Journal of Biomedical Engineering Research
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• v.25 no.5
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• pp.421-430
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• 2004

Clinically, it is almost impossible for a physician to distinguish subtle changes of frequency spectrum by using a stethoscope alone especially in the early stage of thrombus formation. Considering that reliability of mechanical valve is paramount because the failure might end up with patient death, early detection of valve thrombus using noninvasive technique is important. Thus the study was designed to provide a tool for early noninvasive detection of valve thrombus by observing shift of frequency spectrum of acoustic signals with computer aid diagnosis system. A thrombus model was constructed on commercialized mechanical valves using polyurethane or silicon. Polyurethane coating was made on the valve surface, and silicon coating on the sewing ring of the valve. To simulate pannus formation, which is fibrous tissue overgrowth obstructing the valve orifice, the degree of silicone coating on the sewing ring varied from 20％, 40％, 60％ of orifice obstruction. In experiment system, acoustic signals from the valve were measured using microphone and amplifier. The microphone was attached to a coupler to remove environmental noise. Acoustic signals were sampled by an AID converter, frequency spectrum was obtained by the algorithm of spectral analysis. To quantitatively distinguish the frequency peak of the normal valve from that of the thrombosed valves, analysis using a neural network was employed. A return map was applied to evaluate continuous monitoring of valve motion cycle. The in-vivo data also obtained from animals with mechanical valves in circulatory devices as well as patients with mechanical valve replacement for 1 year or longer before. Each spectrum wave showed a primary and secondary peak. The secondary peak showed changes according to the thrombus model. In the mock as well as the animal study, both spectral analysis and 3-layer neural network could differentiate the normal valves from thrombosed valves. In the human study, one of 10 patients showed shift of frequency spectrum, however the presence of valve thrombus was yet to be determined. Conclusively, acoustic signal measurement can be of suggestive as a noninvasive diagnostic tool in early detection of mechanical valve thrombosis.

• Korean Journal of Environmental Agriculture
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• v.20 no.3
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• pp.180-185
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• 2001

Control effects of phosphorous acid were investigated on Phytophthora blight of red pepper plants in greenhouse and field. In vitro test, the mycelial growth of Phytophthora capsici was inhibited by the phosphorous acid more than 97% at 1,000 ${\mu}g$ and 10,000 ${\mu}g$ a.i./mL in the liquid and solid culture, respectively. At concentration of 10 ${\mu}g$ a.i./mL of phosphorous acid, in the liquid culture the mycelial growth of P. capsici was inhibited 46.2%, however inhibited only 4.9% on the soild culture. Zoosporangial formation was also inhibited 89.1% by phosphorous acid at 100 ${\mu}g$ a.i./mL. Phosphorous acid affected more zoosporangial formation of P. capsici than its mycelial growth. At the concentrations of 10,000, 1,000 and 100 ${\mu}g$ a.i./mL of phosphorous acid, germination of zoosporangia was inhibited 100, 84.3 and 44.2%, respectively. Mycelial growth and zoosporangial formation of P. capsici were little affected at the concentration of 10 ${\mu}g$ a.i./mL of phosphorous acid. Cermination of zoosporangia was also little affected at this concentration, however growth of the germ tubes was inhibited and the abnormal mycelial growth was observed. Phosphorous acid suppressed the incidence of Phytophthora blight of red pepper plants up to $77.0{\sim}62.0%$, in greenhouse. Phosphorous acid suppressed the incidence of Phytophthora blight of red pepper plants up to 54.0% at the conventional culture in field. Treatments of phosphorous acid increased up to 113% in height, 135% in number of fruit, and 129% in weight of fruit.

• Korean Journal of Food Science and Technology
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• v.7 no.1
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• pp.37-42
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• 1975

The color intensity (Absorbance at 490nm) and the antioxidant effects of absolute and 90% ethanol extracts obtained from a Maillard-type browning reaction mixture (0. 5M glucose and 0. 5M glycine mixture, heated at $100^{\circ}C$) were determined. The color intensity of the absolute and 90% ethanol extracts were compared with the length of reaction time and the antioxidant effects of the extracts of both types were compared one another. The results obtained are as follows. 1. The color intensity of the absolute ethanol extracts remained almost unchanged as the browning reaction proceeded. The color intensity of the 90% ethanol extracts appeared to increase nearly in proportion to the length of reaction time. 2. The absolute and the 90% ethanol extracts seemed to possess significant antioxidant activity on the autoxidation of an edible soybean oil. which was kept at $45{\pm}0.5^{\circ}C$ for 21 days. It was noteworthy that the absolute ethanol extracts showed stronger antioxidant effects than those of the 90% ethanol extracts, which contained a far greater amount of brown-colored pigments. Since the PVs of the controls in both groups, after the end of the storage period, did not differ much from one another, the possibility of residual water playing some prooxidant role in the substrates containing the 90% ethanol extracts should be ruled out. Extracts of both types obtained at earlier stages of the brownig reaction demonstrated less but comparable antioxidant activity to that of extracts taken at later stages of the reaction. 3. The results of the present study appeared to suggest that the effective antioxidant compounds, produced in the Maillard-type browning reaction, were probably intermediate products such as reductones formed at fairly earlier stages of the browning reaction.

• Journal of Oral Medicine and Pain
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• v.38 no.1
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• pp.35-51
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• 2013

The aims of this study was to observed an effect of antioxidative in cardiac muscle of high fat diet induced obesity rat by treadmill exercise with intensity and time. Thirty-two Sprauge-Dawley rats which were divided into four group. Normal, Control(high fat diet induced obesity rat), Experimental I(high intensity intermittent exercise in high fat diet induced obesity rat), Experimental II(moderate intensity endurance exercise in high fat diet induced obesity rat). The results of this study were as follows: 1. In change of body weight, the outcome of each group significantly difference compared with control. Also, 1 to 3 weeks significantly different compared with pre valu experimental I and II(p<0.001). 2. In change of lipid profile, the outcome of each group significantly difference compared with control(p<0.001). Difference between experimental I and II is not significantly. 3. In change of antioxidative enzymes(SOD, CAT, GPx) in myocardium, there are significant difference between control and experimental II, and also between control and experimental I(p<0.001). 4. In change of antioxidative protein MCR-1, the outcome of each group significantly difference compared with control(p<0.01). Experimental II was most significantly difference than the other group(p<0.001). The above results suggest that treadmill exercise effectively reduced in fat. It would be considered that moderate intensity endurance exercise has an effects on improved antioxidative enzyme in cardiac muscle of high fat diet induced obesity rat.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.29 no.1
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• pp.87-103
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• 1999

Purpose: This study was undertaken to quantitatively estimate the degree of the damage and recovery of the irradiated rat condylar cartilage using the Image Analyzer. Materials and Methods: Experimental animals were 16 male rats of the Sprague-Dawley strain at the age of 20 day irradiated with the dose of 10 Gy in their head and neck region. Four rats were sacrificed at the each of the following time intervals - 1, 4, 7 and 14 days, respectively. The same number of control group animals were sacrificed at the each age of 21. 24, 27 and 34 days, respectively. The specimens were stained with 0.5％ toluidine blue and examined with light microscope. The condylar cartilage was divided into 4 zones; fibrous zone, proliferating zone, upper hypertrophic zone, and lower hypertrophic zone. And then, the proliferating zone was subdivided into 2 layers - upper and lower layer, and upper and lower hypertrophic zone were subdivided into three layers, respectively - upper, middle and lower layer. With the aid of Image Analyzer, morphometric analysis was performed. The thickness, the numerical density of cells, the cell area density, the extracellular matrix area density, the mean area of single cell, the mean area of extracellular matrix per single cell were measured and analysed. Results: In the experimental group, the thickness of the fibrous zone was slightly increased and that of the proliferating zone and the upper and the lower hypertrophic zone was markedly decreased. With time, the thickness of the fibrous zone was gradually increased and that of the proliferating zone and the upper and the lower hypertrophic zone was steadily in the decreased state. The numerical density of cells of the proliferating zone was increased on post-irradiated 1 day, but decreased after post-irradiated 4 day, and that of the upper hypertrophic zone was decreased. The numerical density of cells of the lower hypertrophic zone was decreased in the early stage and then was decreased or not significantly different from that of the control group with time. In the experimental group, the cell area density of the fibrous zone and the proliferating zone was decreased in the early stage and then gradually increased or not significantly different from that of the control group with time. The cell area density of the upper and the lower hypertrophic zone was varied with time. The extracellular matrix area density value were totally opposite to the cell area density values: The mean area of single cell of the fibrous zone and the proliferating zone was .decreased on post-irradiated 1 day, and increased after post-irradiated 4 day. The mean area of single cell of the upper hypertrophic zone was varied with each layer and time. In the experimental group, the mean area of extracellular matrix per single cell of the fibrous zone was not significantly different with control group, and that of the proliferating zone was decreased on post-irradiated 1 day, and increased after post-irradiated 4 day. The mean area of extracellular matrix per single cell of the lower hypertrophic zone was increased in the early stage. and that of upper hypertrophic zone was varied with each layer and time. Conclusion: The condylar cartilages of rats were affected by irradiation, but the changes were vaned with each layer and time. By morphometric analysis. the changes of the cells of the condylar cartilage of irradiated rat could be calculated quantitatively.

• The Journal of Korean Academy of Prosthodontics
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• v.50 no.2
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• pp.92-98
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• 2012

Purpose: The aim of this study was to evaluate the effects of different abutment materials on abutment screw loosening and settling-down effect in conical connection type implant system. Materials and methods: Three types of abutment, cementation, gold UCLA, and metal UCLA abutment were used. Two UCLA groups were fabricated in a similar pattern to cementation abutment. Type III gold alloy and Nickel-Chromium alloy was used for casting gold UCLA abutment and metal UCLA abutment, respectively. Fixture and abutment were tightened to 30 Ncm by using digital torque controller and re-tightening was conducted with same force after 10 minutes. Digital torque gauge was used to measure loosening torque and fixture/abutment length was measured by digital micrometer. Dynamic loads between 25 N and 250 N were applied with $0^{\circ}$ angle to the abutment axis. After loading, fixture/abutment length was re-measured and amount of settlement was calculated. Loosening torque value was also measured for comparison Results: All three groups showed significant differences of length when comparing before and after loading, but there was no significant difference of settling amount in all groups. Loosening torque values were significantly decreased when comparing before and after loading in all groups($P$<.05). However, there was no significant difference in loss of loosening torque values when compared to groups. Conclusion: In internal conical connection type implants, dynamic load affected on settlement and loosening torque of implant, but there was no differences between abutments materials. Likewise gold UCLA abutment, metal UCLA abutment might be able to withstand functional load.